In scanning codes, such as bar codes or dash codes, on a moving sheet of paper, it is critical that 100 percent of the code is read by the optical scanning system. Typically, an optical scanning system opens a detection "window" at a predetermined time after the leading edge of the moving sheet of paper is detected. A detection window is a system controlled location on the sheet of paper where the optical scanning system actively scans to detect the control code. For optical scanning systems including dash code scanners, it is desired that the first dash of the dash code on each sheet of paper is located at or near the center of the detection window. This ensures that 100 percent of the code will be detected by the system. An example of an optical scanning system for scanning dash codes is disclosed in U.S. Pat. No. 4,659,939, issued to John L. Lorenzo on Apr. 21, 1987 and assigned to the assignee of the present invention, which is incorporated herein by reference.
Generally, the codes being scanned are located at the same location on each of the sheets containing the code. Thus, an optical scanning system with a dash code scanner must be initialized to position the detection window so that the first code mark on the sheet is approximately at the center of the detection window. Heretofore, such dash code scanners have been initialized, or set up, by a service technician using a oscilloscope or a logic analyzer. Thus, whenever the code is printed at another location on the sheet or the optical scanning system goes out of tolerance, e.g., too many scan errors occur, it is necessary to initialized the system again to ensure that the first scan mark is centered in the detection window. Again, a service technician is needed for this.
It is an object of the present invention to provide a system and method which simplifies the initialization of the optical scanning system.
It is a further object of the present invention to provide a system and method of initialization of the optical scanning system which does not require a service technician to complete.